Control device



July 13, 1943. c. G. KRONMILLER CONTROL DEVICE Filed NOV. 6, 1940 Fig.2

Fig. 1

INVENTOR Curl G. Kronmillzv ATTORNEY resented July in 1945 STAESS CONTROL DEVICE Application November 6, 1940, Serial 'No. 354,525

The present invention relates to control de vices such as temperature and humidity controls out is more particula" y directed to such a device which is both manually adjustable and adust= able by time as determined by a clockwork.

An object of the invention is to provide a thermostat or like device in which means are pro vided for adjusting the control point according to a timed program.

Another object is to provide a control device in which the usual manual adjustment of the control point is supplemented by means for adjusting the control point accoring to a timed program.

Further objects will be apparent from the following description, from the claims and from the drawing, in which:

Figure 1 is a view of the front of a thermostat embodying the present invention, and

Figure 2 is a. sectional view taken below certain 01' the parts shown in Figure 1.

It is often desirable in processing various products to control their temperature in a definite relation to the elapsed time from the start of the process. Usually this is accomplished by an attendant who watches a thermometer and menually varies the amount of heating or cooling supplied to the chamber or enclosure which contains the product. The particular thermostat illus trated has been designed to control the temperature in tobacco drying barns.

Briefly the invention as illustrated comprises a base on which a bimetal spiral is adiustabiy supported. The blmetal in turn carries a mercury switch. An arm is provided for rotating the himetal in order to select the temperature at which the mercury switch will make and break an electric circuit. A spring run clockwork which is also mounted on base has a shaft extending therefrom by which it is wound and which it also drives. A cam on this shaft determines the position of a l ver adjacent the temperature selecting lever, which lever is provided a spring latch so that the latch will na'ag ably secured to the base i The l3 extends iceyond the bottom oi the base i ii and underneath a temperature indicia plate v in spaced relation to the base 7 screws ii. The base to is so the plate in spaced relation Jo the base in order that the adjusting may extend between the base ii tile 3 16. A fiat disc iii is secured in spaced relam to the adjusting arm i3 at a point adjacent the top edge oi the indicla plate it "to serve as a guide for the arm ii. The outer surface of the disc it extends downwardly beyond the upper edge of the plate IS in such a way that the plate is provides a runway for the disc l8 and adjusting arm l3.

The manual adjusting arm is has secured thereto an angle member 20 on which is mounted a spiral 22 of thermostatic bimetai. A calibrat lng adjustment is provided between the angle member 20 and the adjusting arm 53. Angie member- 20 is pivoted on the stud it on which the adjusting member I3 is pivoted. Member 20 is also provided with a slot 23 through which a screw 24 extends, which screw serves to clamp a spring clip 26, the angle member 20 and the adjusting arm 13 together. It will he seen that the slot 23 provides a range of adjustment between the arm i3 and the angle member 233 whereby the angular relationship between the hlmetal 22 and the adjusting arm is may be varied. The spring clip 25 is bifurcated at its upper end to form a slot which is secured in an annular slot in the stud I4. Tightening of the screw 24 tensions the spring clip 26 to provide a side thrust on the adjusting arm i 3 whereby enough friction is provided so that the arm as will. remain in any of its adjusted positions.

A mercury switch -36 oi conventlcnal type supported by the i on mom a cam ii, an indicia dial 02, and a setting knob 63. is in its unwound position. The cover ii has an opening 35 therein through which the indicia on the dial 412 may be seen. These indicia figures on the dial 02 represent hours. When the clock mechanism is in the unwound position the zero indicia appears in the opening 15 and as the setting knob 33 is turned in a clockwise direction to its limit of movement the eight hour indicia appears through the opening 35. As the clock mechanism is thus wound the cam M is also rotated to move a roller 38. The roller 38 is mounted on the upper end of a lever 50 which is pivoted on the stud i l heretofore mentioned. A spring 52 is secured at its left hand end to a pin 53 mounted in the base i and at its righthand end1to' -the lever 50. The spring 52 serves to bias the roller 00 in a counter-clockwise direction against the cam (ii.

The lever 50 is provided with a lower extension 00 which like the adjusting arm it extends between the base it and the indicia plate 16. This extension 55 lies beneath the adjusting arm i3 and is provided with a spring latch 58 which is secured thereto by means of a pair of rivets 50. The lower extremity of the latch 58 is provided with an upturned portion which is adapted to engage the adjusting arm iii. The portion is sloped so that it is higher at its right hand edge 02 than at its left hand edge 03. Therefore as the clock mechanism is wound and the earn 011 moves the lowerextension 5% of the lever to the left the latch 53 will be forced downwardly as it engages the adjusting arm it. As the extension is brought directly under the adjusting arm the portion iii of the latch 50 will spring upwardly so that its edge 02 will engage the left hand edge of the adjusting arm Then as the clock'mechanism turns the cam iii in a counter-clockwise direction the lever 50 will also be moved in a counter-clockwise direction and the adjusting arm it will be similarly moved. I

As pointed out above the present thermostat was designed particularly for controlling the temperature within tobacco drying barns. For such a purpose it has been found desirable to provide a thermostat in which the temperature can be manually adjusted from 80 F. to 100 F.,

' the temperature raised through an eight hour period from 100 F. to 140 F., and then raised manually from 140 F. to 180 F. The function of the clock mechanism of the present thermostat is to automatically raise the temperature from 100 F. to 140 F. in an eight hour period. Obviously by providing a cam of the desired shape any desired rate of temperature increase throughout this eight hour period may be obtained. When it is desired to start the process the spring latch 53 may be depressed andthe ad usting arm i3 moved to the extreme left as shown in Figure 2. An attendant manually positions the adjusting arm I3 between 80 and 100 at any desired rate. After the arm 13 has been adjusted for a temperature of 100, the setting knob 63 is rotated in a clockwise direction until the cam til has reached the limit of its movement at which setting the latch 58 on the lower extension 50 of the lever 50 will engage the arm 13. The numeral 8 will then appear at the opening 45 indicating that eight hours remain before the temperature will be raised to 140". As the clock mechanism runs down it rotates the cam ii to gradually raise the temperature to 1&0",

As shown in Figure 2 the clock mechanism At this point it is desired to manually adjust the temperature setting of the thermostat to obtain higher temperatures. Obviously the adjusting arm 13 may be moved to the right beyond the position to which the clock mechanism has moved it. The thermostat may be in control of any suitable source of heat such as a fuel burner or steam valve.

The clock mechanism is provided with a slip friction drive so that it may be set in both directions by the setting knob 33. Thus the clock mechanism may be manually set towards the direction in which the thermostat calls for higher temperatures.

It will be seen from the foregoing description that a thermostat has been provided in'which the temperature adjustment can be made both manually and automatically according to a timed program. It is to be understood that I am not to be limited to the particular thermostat described but only by the scope of the appended claims. It should be pointed out that certain of the features of novelty involved are equally applicable to other control devices such as humidity and pressure controllers.

I claim as my invention:

1. In a thermostat, in combination, a thermostatic element, control means operatively connected to said thermostatic element, manually positionable means for adjusting the temperature at which said thermostatic element actuates said control means, and time responsive means manually engageable and disengageable with said manually positionable means for moving said manually positionable means through a continuous timed program of adjustment.

2. In a control device, in combination, a condition responsive element, a control element operatively connected to said condition responsive element, manually positionable, selecting means for adjusting the value of the condition at which said control element will be actuated by said condition responsive element, a clockwork, a cam adapted to be rotated by said clockwork, a member positioned by said cam, and connecting means adapted to cause movement of said selecting means by said member in a single direction.

3. In a control device, in combination, a thermostatic element, a switch adapted to be actuated by said element, manually positionable selecting means for adjusting the temperature at which said switch'will be actuated by said element, a clockwork, a member positioned by said clockwork, and interconnecting means for releasably attaching said selecting means and said member whereby said clockwork may position said selecting means to vary the control temperature of the device when said interconnecting means is effective.

4. In a control device, in combination, a thermostatic element, a switch adapted to be actuated by said element, selecting means for adjusting the temperature at which said switch will be actuated by said element, a clockwork, a member positioned by said clockwork, means for releasably attaching said selecting means to said member, and means for manually winding said clockwork and simultaneously causing engagement of said selecting means by said member.

5. In a thermostat, in combination, a thermostatic element, a control element operatively connected to said thermostatic element and adapted to be actuated thereby, selecting means to adjust the temperature at which said thermostatic .element will actuate said control element, a clockwork, a cam adapted to be rotated by said clockwork, a lever positioned by said cam, and latchlng means for operatively connecting said lever to said selecting means.

6. In a thermostat, in combination, a base, a thermostatic element mounted on said base, an electric switch adapted to be actuated by said thermostatic element, an adjusting member pivoted in said base adapted to vary the control temperature at which said thermostatic element actuates said switch, a cam, a cloclr mechanism mounted on said base and adapted to rotate said cam, a cam follower pivoted in said base, and means positioned by said cam follower for moving said adjusting member, said adjusting member being manually adjustable independently of said cam follower.

7. In a thermostat, in combination, a base, a first lever pivoted on said base, a bimetal element secured to said lever, a mercury switch mounted on said binietal element, a second lever pivoted on said base, a cam for positioning said second lever about its pivot in said base, a cloclrworl: mounted said base for positionin said cam with respect to said base, and means for causing said first lever to move with said whereby the control temperature ill be varied as said clockwork said first lever being manually endently of said second lever.

e. the. nos-tat, in. combination, thSHTlU- static elemen", control means operatively connected to said thermostatic element, manually po sitionable means for adjusting the temperature at which said thermostatic element actuates said control means, a spring driven clockwork having a winding lrnob, a cam rotatable with said wind ing knob, a lever adapted to be positioned by said earn, and a latch on said lever for engaging said manually positionable means whe'nsaid clockwork: is wound whereby said clockwork will. be efiective to vary the control point of the thermostat.

9. a control device, in combination, a con" dltion responsive element, control means operatively connected to said condition responsive element, 2. cover for said condition responsive means and said control means, manually positionable means extending outside of said cover for adjusting the value of the condition at which said con dition responsive element actuates said control means, and time responsive means for continuously adjusting said manually positionable means during a predetermined continuous timed pro-- gram.

10. In. a thermostat, in combination, a thermostatic elernent, control means operatively connected to said thermostatic element, adjustable means for determining the temperature at which said temperature responsive means actuates said control means, said adjustable means being manually adjustable, time responsive means, and means to connect said time responsive means and said adjustable means when said adjustable means is within a predetermined range for continuously adjusting the temperature setting of said thermostat to a predetermined value which is independent of any previous temperature setting or" said adjustable means within the predetermined range.

11. In a control device, in combination, a thermostatic element, a switch adapted to be actuated by said element, selecting means for adjusting the temperature at which said switch will be actuated by said element, a clockwork, a member positioned by said clockwork, means for releaspositionable a connector on said lever,

l and thereby to actuate said lever to an initial ably attaching said selecting means to said memher, and means for manually winding said clock worlr for causing engagement of said selecting means by said member without moving said selecting means,

12. In a thermostat, in combination, a then mostatic element, control means actuated by said thermostatic element, a member for determining the temperature at which said thermostatic eleelement will actuate said control element, t responsive means, a lever positioned by said i responsive means, and means for 1-: opel anvely con-- ,neans.

necting l ver a1 id sele I ,1 automatic temper t vice o described, an a me oh thermostatic sw a pivoted co' connected to ca l means an will, for adjustin the switch meat;

the active temperature-range there table clocir motor including a drive sh on said shaft, pivoted lever engaging aid for pivotal displacement thereby, relca adapted for ope atively connecting said lever to said control arm, and means for turning said shaft to v up the clock motor andcoincidentally there tate said cam to airinitial operative 1 position for connection said connector, with said control arm, said clocl; motor when wound, rotating said cam and thereby actuating said lever to cause pivotal displacement or said control arm in an automatic and continuous manner, whereby to cause continuous adjustment of said switch means to change the active temperature range thereof.

15. In an automatic temperature control device of the character described, a pivoted member, a thermostatic switch means carried by said member, a pivoted control arm connected to said member and operable at will, to pivotally displace said member and switch means thereon, for changing the active ternperature-responsive range of said thermostatic switch means, a lever pivoted coaxially with said control arm, a re leasable connector on said lever, adapted for conmeeting the lever to said control arm, a re-settable clock motor including a drive shaft, a cam on said shaft engaging said pivoted lever, and means for turning said shaft to thereby wind up'said clock motor and coincidentally therewith, to rolate said cam to an initial operative position, said cam in attaining such initial position, thereby displacing said lever to an initial postion for connection by said connector, with said control arm, the subsequent rota ion of said cam said clock motor thereby eff g a pivotal displacement of said lever automatically and continuously at a predetermined rate and for a predetermined time period, and throng i said connector, a corresponding displacement of said control arm, to efiect an automatic and continuous change in the active temperature-responsive range oi said thermostatic switch means.

16. A temperature control device of the character described, comprising co-axially pivoted levers, a thermostatic switch means carried by one of said levers and adjustable in response to pivotal movement of said lever, for varying the active temperature-range of the switch means, a time-operated cam engaging another of said levers for pivotal actuation thereof, and a releasable connector on one of the levers, adapted for connecting the levers together for concurrent pivotal movement in response to the operation of said cam.

17. A'tempera-ture control device of the character described, comprising a pivoted member, a thermostatic switch means carried by said member and being adjustable in response to pivotal movement of said member, for varying the active temperature-range of the switch means, coaxially pivoted levers, one or said levers being connected to said member and movable at will, to effect pivotal movement of the member, a time-operated cam engaging another or" said levers for pivotal actuation thereof, and a releasable connector on one of the levers, adapted for connectting said levers together for concurrent pivotal movement in response to the operation of said cam.

18. A temperature control device of the character described, comprising a pivoted member, a

asaaiee thermostatic switch means caried by said member and being adjustable by pivotal movement of the member, for varying the active temperaturerange of the switch means, a pivoted lever connected to said member and manually movable at will, between predetermined limits, to effect a corresponding pivotal movement of said member, a time-operated cam, a second pivoted lever engaging said cam for pivotal actuation thereby, and means on one of said levers adapted for effecting a releasable connection of said levers for concurrent pivotal movement in response to the operation of said cam.

19. In a thermostat, in combination, a base, a thermostatic element mounted on said base, an electric switch adapted to be actuated by said thermostatic element, an adjusting member pivoted in said base adapted to vary the control temperature at which said thermostatic element actuates said switch, a cam, a clock mechanism mounted on said base and adapted to rotate said cam, a cam follower for continuously engaging said cam, and means positioned by said cam follower for moving said adjusting member, said cam and said cam follower cooperating in such a manner as to continuously vary the position of said means during the period of rotation of said cam by said clock mechanism, and said adjusting member being manually adjustable independently of said cam follower.

CARL G. KRONMILLER. 

